Indian security forces shot dead four rioters Tuesday, taking the death toll from ethnic violence in India's remote northeast to 26, police officials said.
Police issued shoot-on-sight orders late Monday in an attempt to quell ethnic violence in Assam state, after rioters burnt shops and houses and attacked rival gangs.
"Four people were killed in two separate incidents in Western Assam when they tried to indulge in acts of arson," the state's police chief J. N. Choudhury told reporters.
"The situation is tense and we are trying our best to quell the violence with some tough measures."
Indian soldiers and paramilitary troops have been on patrol to try to calm the unrest that started Friday, triggered by long-standing territorial disputes.
Fighting has flared between Bodo tribal groups and Muslim settlers in the west of Assam state, where more than 40,000 villagers have fled their homes to shelter in government buildings, schools and relief camps.
"Despite all the action, the situation continues to be tense and volatile. We want more security forces, especially reinforcements of army soldiers," Hagrama Mohilary, head of the Bodoland Territorial Council, a local government body, told AFP.
Local television channels broadcast pictures of several homes that had been set ablaze by rioters.
"Police, army and paramilitary troopers have intensified patrols and a 24-hour, indefinite curfew has been imposed," Assam Forest Minister Rockybul Hussain said from the worst-hit district of Kokrajhar.
The shoot-on-sight orders mean mobs breaking the curfew can be shot without warning.
"We have lost everything in the violence. Our houses have all been razed to ground with mobs setting ablaze our properties," said Rabiul Islam, who has taken shelter in one of the government's relief camps.
The estimated 40,000 who have fled their homes include many women and children.
"We are providing food and basic medicines to those in need," Nazrul Islam, a senior state minister, told AFP by telephone.
The Press Trust of India news agency said the fighting started when two Muslim student leaders were shot and seriously injured in Kokrajhar, leading to revenge strikes on Bodo groups.
Northeast India, which is linked to the rest of the country by a narrow land bridge, has seen decades of friction among ethnic and separatist groups, though some of the biggest rebel movements have recently started peace talks with the government.